Can rocephin (ceftriaxone) cause anaphylactic shock if you are given a large dose and allegergic to penicillin how much could cause that?

Rocephin (ceftriaxone) allergy: Rocephin (ceftriaxone) belongs to the cephalosporin group of antibiotics. Cephalosporins are chemically related to penicillin and have been shown to cross react in individuals allergic to penicillin in 5-7% of patients. The reactions can vary from hives and itching to throat closing and anaphylactic shock. Giving Rocephin (ceftriaxone) to someone who is allergic to penicillin could result in anaphylaxis.